$100 Absarokee combined water-sewer hike possible

Monthly sewer rates in Absarokee could increase to as high as $82.38 in order to comply with state regulations, Great West Engineering consultants said during a public meeting at the Cobblestone on March 9.
That’s on top of a $51.77 monthly water bill proposed for Absarokee customers. By 2018, the combined base rate bills could increase about $100 – from about $34 a month just a year ago to $134, a 400 percent increase.
In the case of water bills, the increase will go to fixing leaky mains, a project the Absarokee Water & Sewer District board feels makes good sense.
But for Stillwater County, which owns the community’s sewer system, investing $4.9 million to upgrade the sewage treatment plant is not a choice – there have been too many permit violations, and the system must be brought into compliance, consulting engineer Craig Pozega said.

Mandated changes
The Absarokee plant, which discharges into Rosebud Creek – a stream with “high quality” water – was cited for being in violation for E.coli in 2010, 2011 and 2012 and for biochemical oxygen demand in 2007, 2008, 2010 and 2011.
The Montana Department of Environmental Quality issued an administrative order on consent in 2013, a legal document that ordered the county to comply with its wastewater discharge permit by the end of 2018. Failure to comply could result in a $10,000 per day fine up to $100,000.
One of the DEQ requirements is for a preliminary engineering report to analyze the current system and develop alternatives to bring the system into compliance, consulting engineer Collette Anderson said. The engineering report is also required by funding agencies the county will turn to for funding grants and low interest loans.
To build up capital reserves and to satisfy funding agencies, the Stillwater County Commissioners approved a sewer rate hike last August that will incrementally increase the monthly bill from $17.05 to $32.76 by 2018. The Absarokee sewer rate last saw an increase in 2003.
But to pay for the preferred alternative proposed in the engineering report, the monthly bill in Absarokee could increase even more.

Depending on the funding scenario, future monthly sewer bills could range from a low of $50.98 to a high of $82.38 over three years.
Bringing outdated equipment into compliance is only part of the story – the Absarokee plant must also meet some stricter and new discharge limits, Anderson said.
To meet E.coli standards, the engineers propose replacing the treatment plant’s current disinfection system – aging ultraviolet equipment.
But meeting a new limit on ammonia – which is considered toxic to fish – may be more difficult. For one thing, treatment systems that address ammonia also produce nitrates, which have not been a problem in the past for the Absarokee plant but could be someday in the future, Anderson said.
One advantage the Absarokee plant has is its lagoons – a waiver for total nitrogen and total phosphorus currently exists for small communities that cannot afford to replace their lagoons with a mechanical treatment plant, Anderson said.
The preferred alternative also would provide for 0.8 percent annual growth over 20 years to 1,253 users – about 200 more users in a community that has seen a moratorium on sewer hookups since the 1990s. But how long the new system will last or hold up to future permit changes is unknown, Anderson said.
According to the engineers’ proposed timeline for the treatment plant upgrade, grant applications would be submitted in May, design work would take place in summer and fall 2017, construction bids would take place in February 2018, and construction would start in May 2018.
Commissioner Gerald Dell said a decision about whether to go ahead with the $4.9 million project will be made in about three weeks so grant applications can be submitted on time.
Both the water district board and the commissioners say they want to phase in the new rates over three years, but some people in the community wonder why the rates weren’t phased in years ago.

Three alternatives
The annual operation cost for the Absarokee plant is about $110,000. The plant’s three lagoons are shallow and don’t provide sufficient retention time, Anderson said.
“They would not be built that way today,” she said. “As they exist now, they can’t handle new permit requirements – especially ammonia.”
Earlier engineering studies focused on Absarokee’s collection system problems. The collection system is 19 percent clay pipe and 46 percent asbestos-cement pipe. Storm water and groundwater leaks into manholes and pipes, increasing the average flow to the treatment plant from 133,000 gallons per day in the non-irrigation season to 753,477 during irrigation season.
Some collection problems have been addressed, and future repairs could allow for more growth in the community, Pozega said. But the cost of repairing the collection system is high, and it wouldn’t address other sources of inflow to the treatment plant – including roof drains and sump pumps residents have connected to the sewer system.
“We need to focus on the treatment plant,” he said.
Adding two new lagoons on the five adjacent acres owned by the county, as suggested in a previous engineering report, would not address the new ammonia limit, Pozega said. Instead, the engineers looked at 16 alternative treatment plant solutions and whittled them down to three.
• The “storage and irrigation” system calls for storing wastewater through the winter and then spraying it on cropland in the summer. The $9.8 million system would not require a discharge permit into Rosebud Creek and would be simple to operate – the increase to the annual operating budget would be about $32,250.
But the system requires about 250 acres, and very little land around Absarokee has the correct soils for land-applying. Acquiring suitable land and pumping wastewater to that site is what drives up the system’s cost. And the impact of future permit changes is unknown, Anderson said.
• The “extended aeration activated sludge” system, sold under the Biolac trade name, is a mechanical system with a small footprint – the system could fit inside one of Absarokee’s existing lagoons.
The system provides good secondary treatment as required by the EPA, converts ammonia to nitrates and nitrates to nitrogen gas, and provides good retention time, Anderson said. But while its capital cost is relatively low at $5.6 million, its operational costs are high – about $55,980 more per year.
The Biolac system uses lots of machinery and would require an additional operator and a higher-class operator license. Finding and retaining qualified operators is a common problem for small Montana towns, Pozega pointed out.
Additional prescreening must be done at a headworks, and sludge must be removed and hauled away weekly, compared to once every 20 years with the preferred alternative. Absarokee would also lose its lagoon variance by installing a Biolac system, meaning they might have to deal with strict limits for total nitrogen and total phosphorus – both expensive to deal with.
• The preferred alternative, the “existing partial mix lagoons with submerged attached growth reactor” system, would be simple to operate and would have a 20-year life. The initial cost would be $4.9 million, and annual operating costs would increase by about $42,150.
A new lagoon would be built with an aerated gravel bed. A bio-film on the rocks would deal with biochemical oxygen demand, total suspended solids and ammonia.
Construction would include removing sludge from the existing lagoons, which would then be lined and used to handle the overall system’s high volume. And Absarokee would retain its lagoon variance.